Production and Consumption of 1,6-Hexanediol in China   

By Jia Dongmei, China National Chemical Information Center

1,6-Hexanediol (HDO) is an emerging fine chemical raw material. Because of its unique performance and non-corrosiveness, it can be used to produce a new range of novel fine chemicals and has increasingly wide applications in UV coatings, adhesives, polyester, plasticizers, pesticides, pharmaceuticals and dyes. It is mainly used to improve the mechanical strength of products and their resistance to hydrolysis, heat and chemical reagents, and has become known as "a new cornerstone for organic synthesis."

1. Production

Before 2008, China had no large-scale HDO producers, and to meet the domestic demand, depended heavily on imported products, mainly from BASF (Germany), Ube (Japan) and LANXESS (Germany). BASF is the world's largest manufacturer of HDO. By the end of 2006, the production capacity of its HDO plant in Ludwigshafen, Germany had been expanded by more than 20%, and the company's total HDO capacity, including a facility in Freeport, Texas, had reached 42 000 t/a. Ube has HDO production facilities in Japan and Spain, with a total capacity of about 10 000 t/a. The company's Spain-based subsidiary, PQM Company has an annual HDO output of about 4 000 tons, about half of which is used to develop polycarbonate diol ester (PCD) adhesive for automobiles. PCD is a raw material for advanced polyurethane products and can also be used for the production of sealants for automobile seats and window frames and to make water dispersible latex for automotive interior floors. In addition, Ube Fine Chemicals (Asia) Limited, a subsidiary of Ube, will build a 6 000 t/a HDO plant in Thailand's Royong, using the patented technology of Ube. The plant will co-produce 1,5-pentanediol, with a total estimated investment of US$571 million, and is expected to be completed in the first quarter of 2011.
   As of the end of 2010, there were only three HDO manufacturers in China, with a total production capacity of 16 500 t/a, and a total annual output of 12 000 t/a, as shown in Table 1.

Table 1 Major HDO producers in China in 2010
Producer    Capacity (t/a)    Output (ton)    Remarks
Lishui Nanming Chemical Co Ltd    10000    8000    Built in November 2008
Fushun Tianfu Chemicals Co Ltd    5000    3000    Built in November 2009
Liaoning Haitai Technology Development Co Ltd    1500    1000    Built in September 2010. Capacity will be expanded to 3000 t /a within a couple of years.
Total    16500    12000

   In 2006, the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences and PetroChina Liaoyang Petrochemical Company jointly developed China's first HDO pilot unit (200 t/a) with independent intellectual property rights. This unit made HDO from 1,6-dimethyl adipate by medium-pressure hydrogenation and was successfully operated by Liaoyang Petrochemical Company.
   In November 2008, the 10 000 t/a HDO unit of Lishui Nanming Chemical Co Ltd, which is located in Lishui Economic Development Zone, Zhejiang Province, was put into production. Its actual annual HDO output is 8 000 tons. The company is mainly engaged in the research, development, production and sales of fine chemicals. Since its inception in 1997, with its own technological strength, the company has provided dozens of high-quality rare intermediates, monomers and additives for the manufacture of pharmaceuticals, electronic chemicals and novel special-purpose and multi-functional materials. This 10 000 t/a unit is China's first large-scale HDO plant, and its product is even ordered by France's Total S.A.
   In November 2009, Fushun Tianfu Chemicals Co Ltd (Tianfu Chemicals) put its 5 000 t/a HDO unit and 1 000 t/a cyclopentanol unit into operation. The core technology of the two units was developed by Shenyang University of Technology, and their combined investment was more than RMB100 million. The company was founded in 2006 and specializes in the development, production and sales of fine chemical products, including HDO and cyclopentanol. It covers an area of more than 20 hectares in the Fushun Hi-Tech Industrial Park. The company is currently planning to build a 20 000 t/a HDO plant, with a total investment of RMB250 million. This project will be completed in 2011. By then, the company will be the world's second largest HDO producer.
    Liaoning Haitai Technology Development Co Ltd completed a 1500 t/a HDO unit in September 2010 and plans to expand its HDO capacity to 3000 t /a within a couple of years. Like Tianfu Chemicals, the company is located in Fushu, Liaoning province.

2. Price

In the four years from 2007 to 2010, the year's average price of HDO in China was RMB41 000 /t, RMB36 000 /t, RMB32 000 /t and RMB38 000 /t, respectively. For example, in October 2010, HDO prices were RMB38 000 - 41000 /t, with domestically-made HDO selling at about RMB38 000 /t and imported HDO at about RMB41 000 /t. HDO prices are mainly subject to price changes of its main raw material - adipic acid.

3. Consumption

In China, HDO is mainly used in UV coatings, adhesives, synthetic leather pulp and soles, polyurethane coatings, plasticizers and epoxy resin. In recent years, makers of UV coatings are the largest consumers of HDO, accounting for more than 1/3 of the total, followed by makers of adhesives, pulp and synthetic leather soles, polyurethane coatings, plasticizers and epoxy resin.

(1) UV coatings

UV coatings contain very little or no solvent, have very low VOC (volatile organic compounds) emissions and can be almost 100% cured by UV radiation, so they have developed rapidly in China in the past decade. Reactive monomers are important components of UV coatings. They not only regulate the viscosity of the coatings but also play an important role in the performance of the coatings. One commonly used active monomer is 1,6-hexanediol diacrylate (HDDA), which is made from HDO and acrylic acid by catalytic esterification. HDDA is a low-viscosity and fast-curing monomer, has low volatility, flexibility and good resistance to hydrolysis, heat and chemical reagents and is thus widely used in light-cured coatings, inks, sealing rubber and plastic products. In 2010, China's HDDA output was about 7 000 tons. Major HDDA manufacturers in China are Jiangsu Litian Technology Co Ltd, Tianjin Tianjiao Radiation-curable Materials Co Ltd, Cytec Industries (Shanghai) Inc, Yixing Honghui Chemical Co Ltd and Sanmu Group.

(2) Adhesives

In the field of adhesives, HDO is mainly used in the production of polyurethane adhesives, which feature excellent low-temperature performance, low curing temperature, excellent flexibility, good impact resistance and excellent infiltration and adhesion to a variety of materials and are mainly used for room temperature and fast curing, especially for bonding dissimilar materials that have different coefficients of expansion. HDO can be used to produce high-grade polyurethane adhesives with special performance factors such as resistance to yellowing.

(3) Polyester resins

HDO can be used to improve the performance of unsaturated polyester resins. HDO-based unsaturated polyester resins are more difficult to hydrolyze and have better flexibility than other short-carbon-chain diols-based unsaturated polyester resins like glycol polyester, so HDO can improve the alkali resistance of polyester resins and their adhesion with glass fibers. In the aspect of saturated polyeste